Loud-speaker



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E. H. FOLEY LOUD SPEAKER .Filed June 2. 1925 shaun-sheet 4 fukin,

Sept 9, 1930. E. H. FoLEY '1,775,453

LOUD SPEAKER Filed June V2, 1925 6 Sheets-Sheet 5 E. H. FOLEY LOUD SPEAKER Sept. 9, l1930.

GSheets-Sheet 6 Filed June 2, 1925 Patented Sept. 9, 1930 UNITED STATES PATENT OFFICE EARL HFOEEY, OF SEATTLE, WASHINGTON, ASSIGNORJBY MESNE ASSIGNMENTS, 0F NINETY-NINE ONE HUNDREDTHS TO INTERNATIONAL ACOUSTIGRAPH COMPANY, A

CORPORATION OF WASHINGTON LOUD-SPEAKER Application led .Tune 2,

instrument of the loud speaker type,'by

associating with the magnetic unit of sound impulse translation plural diaphragms, preferably two in number, and each lprovided with similar associated mechanism for rendering a fine quality of reproduction.

According to the concept embodied in the present concrete forms of my invention suit able means in the form of independently ad- .justable members are provided on each side of the usual "'loud speaker diaphragm so that a wide margin of variation can be attained in the extent of the air cushion yacting `upon the said diaphragm to the end that perfect reproduction of the tones of widely different instruments, lsuch as a violin Aand a trombone, can be attained in a simple and effective manner.

Another aspect of my inventive concept contemplates the utilization of a single magnetic unit of sound impulse translation to influence simultaneously and accurately a pair of relatively independent diaphragms,

with each of which. is associated the necessary mechanical parts, and my improved devices for modifying the respective ail cushioning mediums, so that a more effective and much finer quality of reproduction is attained.

Other and equally important objects of my invention may be briefiy defined as follows: first, the provision of a unique double coinpartment housing or casing for my double diaphragm loud speaker; second, the pro'- vision of unitary and integral means for adr j usting the throat and one of the air cushions of my instrument; third, the provision of siin- 1925. Serial No. 34,329.

ple and effective means for operatively connecting for effective operation two, three or more diaphragms with a single magnetic unit, and; fourth, the development 'of a compact, durable, simple and effective instrument of the type defined which may be commercially produced at a relatively small price and the parts of which may be repaired and replaced with facility, and which has novel sound,`

reflecting means in conjunction with the diaphragms.

To these and other equally important ends my improved instrument of the loud speaker type consists in the construction, combination and arrangement of parts described hereinafter, but interpretation of the scope of my invention should only be conclusive when made in the light of-the subjoined claims.

Thel principal embodiments and several modifications of my loud speaker are represented by -wa'y of example in the accompanying drawings, wherein r--- Figure 1 is a side elevation of one of the preferred forms of my invention wherein the use of an armature in the magnetic unit is dispensed with by the use of metallic on one of the diaphragms,

, Figure 2 is an end view of the form shown in Figure l,

Figure 3 is a side elevation, partly in section, of a slightly modified and preferred form of my invention wherein conical sound reflectors are shown,

Figure 4 is an end in Figure 3, i

Figure 5 is a side elevation, partly in section, of a modified double diaphragm form of my invention having, among other things, damping plates,

view of the form shown plates y Figure 6 is a sectional side elevation of another modified form of my invention in which a single diaphragm is utilized,` f Figure 7 is a top plan view of the throat and air cushion adjusting element of the modified forms shown in Figures 5 and 6,- y

Figure 8 is a top plan view of the double plate adjusting `member or damperfutilized with the various forms of my invention in- 1 cluding those shown in Figures 2, 5 and 6, and

Figure 9 is a side elevation of the 'casing used with my single diaphragm loud speaker shown in Figure 6, and

Figure 10 is atop plan view of the casing shown in elevation in Figure 9.

Inthe drawings wherein like characters of reference designate like or similar parts throughout the severa-l views g- 1 In the form ot' my invention shown in Figure 1, the numerals (100) (101) and (102) designate the several fianged housings of my device within which the respective diaphragms (103), (104) and (105) are rctained by gaskets (106). Mounted on each of the housings is a cover plate (107), and each coverplate has an opening (108) therein and a flange likevextension (109). The extensions function to facilitate the projection of sound waves from the diaphragms, 'and the cover plates are each convexed to form sound chambers (110). The several housings are secured together in rigid and properly spaced positions to form a unitary device by retaining bars (111), the same being secured to the housings by screws (112). The dia hragm (104) has mounted centrally thereo metal disks (113), and connecting the said disks, one with diaphragm (103) and the other with diaphragm (105) are rods (114)-a single rod may be used if so desired it being simply necessary to project the same through thev disks and diaphragm. Mounted by studs (115) between housings (100) and (102) is a permanent magnet (116), the arms (117) and (118) of which embrace the housing (101) and the diaphragm retained thereby. Carried by each of the arms is a pole piece (119), and said pole pieces are arranged so that the disks (113) are disposed therebetween with the rods (114) extending through the pole pieces, whereby the disks are influenced by the. modifications in electrical current occasioned by soundimpulses to vibrate the diaphragm (,104). (104) is operably connected by the rod, or rods, to diaphragme (103) and (105) they will all vibrate in unison to great-ly magnify vand render more effective the translation of sound impulses.

In Figures 3 and 4 are shown another modified form of my invention in which the nu. meral (200) designates a semi-cylindrical casing adapted to be supported on a. suit-able base (such as a table, .not shown) by legs (201). Mounted on the respective ends of the casing are ilanged interiorly screw threaded housings (202) and (203), within which are mounted by gaskets (204) the diaphragme (205) and (206). The diaphragms are connected with each other at their centers by a rod (207) which is engaged by an armature (208) forming a part-of a magnetic unit having a permanent magnet (209) and coils (not shown). (210) designates a partitioning member between the diaphragms and (211) Inasmuch as diaphragm' ments (213) and (214) which form sound chambers (215) 'and which may be adjusted to regulate the size of the sound chambers, and each cover plate is formed with a central opening. (216). An outwardly flared flange member (217) surrounds the opening (216) in cover element (213), while cover element (214) is enlarged and has a beveled surface (218). Mounted on cover element (213) is a cylidrical boxing (219) having a conical end (220) constituting a sound reflector. Each ofthe housings (202) and (203) also carry flanged plates (221) which are formed with openings designated (222). Rotatably mounted on each plate (221) is a dampinfr plate (223) and each damping plate is formed with openings (224) adapted to register, when desired, with the openings (222) in the respective plates (221). The purpose of the )lates 221 and 223 is to provide means wherey the bodies of air on the respective sides of the diaphragms which they enclose may be rendered more or less adaptable to com ression due to vibrations, or movement o the diaphragms, depending respectively upon whether openings (222) areopen or closed. The housings (202) and (203) are reinforced by bars (225), and t-he entire unit is rendered handily transportable by a handle (226).

In the forms of my invention shown in Figures 5 to 10, the numeral v(1) designates ,a cy-4 lindrical casing formed with a base (2) and the double diaphragm tvpe shown in Figure 5 is provided wit-h upper and lower sections (3) and (4) respectively, separated by a partitioning member and secured together by suitable screws (6). The casing (1) is further provided With al pluralit7 of annularly aligned openings (7) and other openings (8) in the top (9) thereof. Centrally of the top of the casing is formed an opening (10) for receiving the neck (11) of ahorn (12); an annular flange (13) being formed about said opening to more adequately support the horn.

In the double diaphragm type shown in Figure 5 there is mounted on the partitioning member (5) a magnetic unit generally designated by (14). Said magnetic unit comprises essentially a. coil (15),v a permanent.

magnet (16) .and an armature (17). Engaged bythe armature4 (17) is a vertically arranged rod (18) vwhich engages atene end Y and (20) are properly mounted each bet-Ween gaskets (25) supported on the abutment face (26) formed by the steps of the element (21), and held in place by the rings(27).

Adjustably engaged each with the screwthreaded face of the portions (23) of elements I (21) are caps (28), each having a conical central portion (29) formed with a flanged opening (30) for receiving the neck (11) of each of the horns (12). Hereinafter adjustment with reference to the neck of the horn will be termed the throat adjustment. The caps (28) are also provided with lugs (31) which may be engaged by any suitable instrument (not shown) inserted into the casing through openings (8) in the top (9) of section (3) and openings `(7') of section (4) to turn the cap to effect the necessary adjustments. Obviously any adjustment ofthe caps will correspondingly restrict the chambers above the diaphragms which yserves to regulate the loudness and quality of reproduction through the diaphragm.

In order to modify the air cushions affecting the opposite sides of the diaphragms, I have mounted adjacent to each of them the double plates (32) and (33), the plate (32) beinghereinafter termed the damper, and these are connected for relative rotation by studs (34). Each of the plates is provided with a plurality of circularly arranged, spaced openings (35) which are adapted to be moved into and out of register when one plate is moved with respect to the other. The damper plates (32) are also provided each with an annular depending flange (36) which in turn is bent outwardly to form a lip (37). The flanges arey exteriorly screwthreaded as at 38) for engagement with the screwthreaded faces of portions (22) of elements (21). Each of the plates (33) is provided with a detent (39) which extends through one of the openings (7) to facilitate moving the plates (33) with respect to theplates (32) to open, or vpartially open, or close the openings therein whereby to render the body of air enclosed on that side of the diaphragme more or less responsive to vibration depending upon whether the openings (35) are open or closed.

In the single diaphragm form of my instrument of the loud speaker type shown in Figure 6, the mechanical features incident to either of the sections and (4) of the double diaphragm type are duplicated except `that the magnetic unit (14) is mounted in the single diaphragm type on a removable base closure (40). In this form, the rod (18) is `engaged with only one diaphragm, here designated by (19') In each form of my invention the magnetic units are provided with a cover plate (41) which serves an obvious purpose.

In operation (and referring alike to the various forms herein shown and described) my loud speaker is connected in circuit with any type of radio apparatus, or the like, and

the electrical impulses significant o the sounds to be reproduced are transmitted to my coils which form one of the elements of my electro-magnetic units comprising the magnets, cores and armatures. The arma` tures w1ll accordingly be alie'cted to actute the diaphragms connected thereto to repro'- duce audibly the sounds which the electrical I impulses are significant of. However, since each of my armatures, herein described, are respectively connected to more than 011e diaphragm the magnitude of the reproduction will be in direct proportion to the number of diaphragms ai'ected by each individual f tight (confined) or open (unconfined). A-

body of air which is trapped (or confined' in a completely closed chamber) is less responsive or sensitive to compression or distension, than a body of air which is open to the atmosphere in general. Since, therefore, a confined body of air resists changes in volume which would be induced by the movement of theA diaphragm, then the extent of movement of each of my diaphragms may be accurately and finely regulated by moving into or out of register the openings in the several plates. A much finer quality of reproduction is thus attained. While in the foregoing there has been illustrated and described such combination and arrangement of elements as constitute the preferred embodiments of my invention, it is nevertheless desired to emphasize the fact that interpretation of the invention should only be conclusive when made in the light of the subjoined claims.

1. In an instrument for reproducing sound including a diaphragm, and means for actuating the same, said diaphragm having a chamber on both sides thereof, one chamber having'free communication with the atmosphere, adjustable means in the other chamber for opening the chamber to the atmosphere or completely closing it, in combination with a h'orn communicating with the first named chamber. i

2. In an .instrument for reproducing sound including a diaphragm, and means for actuating the same, said diaphragm havin-g a including a diaphragm and means for actuating the same, said diaphragm having a chamber on both sides thereof, adjustable means for restricting the size of one chamber, and adjustable means in the other chamber for gradually opening or closing communication of said chamber with the atmosphere.

4. The combination in an instrument for the reproduction -of sound, sensitive means for translating sound impulses, means for adjusti ng the size of the sound chamber in front of the sensitive means, and adjustable devices for regulating the air pressure in the back of said sensitive means.

5. The combination in an instrument for the reproduction of sound, a diaphragm for translating sound impulses, means for adjusting the size of the sound chamber in front of the diaphragm, and adjustable devices in back of the diaphragm for regulating the air pressure affecting the same.

6. The combination in an instrument for the reproduction of sound, a diaphragm for translating sound impulses, an adjustable cover plate for the sound chamber in front o f the diaphragm to adjust the size of the sound chamber, and adjusting plates having registering openings therein located in back of the diaphragm, and one plate being movable with respect to the other for regulating the air pressure in back of the diaphragm.

7. The combination in an instrument for the reproduction of sound, a plurality of sensitive means for translating sound impulses, and opera-tively connected together to function as a unit, and relatively independent devices, one associated with each of said sensitive means, for individually regulating the air pressure on each of said sensitive means.

8. The combination in an instrument for the reproduction of sound, a plurality of diaphragm-s for translating sound impulses, and operatively connected together to function as a unit, each diaphragm having a closed chamber on one side thereof, and relatively 1ndependent, adjustable devices, one in each chamber, for individually regulating the air pressure on each of said diaphragms.

9. The combination in an instrument for the reproduction of sound, a plurality of sen- 'sitive means lfor translating sound impulses,

relatively independent means, one for each diaphragm, for adjusting, the size of the sound chamber for each diaphragm, said diaphragms operatively connected together to function as a unit, each diaphragm having a closed chamber on the back side thereof, and relatively independent, adjustable devices, one for each closed chamber, yfor individually regulating the air pressure in back of each diaphragm.

10. In an instrument for reproducing sound including a diaphragm and means for actuating same, a supporting member in 'Which the diaphragm is mounted, a cover member for the supporting element and having a throat portion for attachment to a horn and spaced from the diaphragm to form a sound box, said cover member being adjustably mounted on the support to vary the size of the sound box, another cover member for the supporting member and spaced from the diaphragm to form a chamber on the side of the diaphragm opposite the sound box, and formed with openings therein to admit air, and adjustable means on the latter cover member for closing the openings for varying the pressure on the diaphragm.

11. In an instrument for reproducing sound including a diaphragm and means for actuating the diaphragm, a supporting frame between the edges of which the diaphragm is Ymounted, a cover member for one side of the frame and having a throat portion for attachment to a horn, said coverV member being spaced from the diaphragm to form a sound box and adjustably mounted With respect to the supporting frame to adjust the.

size ofthe chamber.

12. In an instrument for reproducing sound including a diaphragm and means fori actuating the same, a supporting frame between the edges of which the diaphragm is mounted, a cover plate removably carried by the supporting frame on one side of the diaphragm and spaced therefrom to form a chamber, said cover plate having openings therein communicating With the atmosphere, and an adjustable member on the cover plate. for closing the openings to vary the -air pressure on the diaphragm.

13. In an instrument sound, a diaphragm, a housing for the diaphragm, said housing having an interiorly stepped Wall forming an abutment against which the diaphragm is mounted in spaced relationship to the edges of the housing, the Walls being screwthreaded from the edges of the housing toward the diaphragm, cover elements for the housing carried on each side of the diaphragm and spaced therefrom to form chambers and detachably engaged with the screw threads, one cover element Iiaving a connection With a horn or the like and being adjustable to vary the size of the chamber on that side of the diaphragm, and the other cover element having means thereon for regulating admission of air to the chamber on that side-of the diaphragm to adjust the pressure on the diaphragm.

14. In an instrument for reproducing sound, a plurality of sound sensitive devices, housings inwhich the sound sensitive devices are mounted and forming independent sound chambers therefor, means connecting said housings together, and a common instrumentality-ffor actuating all of said sound sensitivedevices in unison.

15. In an instrument for reproducing sound, a plurality of sound sensitive devices,

for reproducing housings in which the sound sensitive devices are mounted and forming chambers on both sides of the diaphragms, individually adjustable means for regulating the air pressure in one of the housings of each o the diaphragms, means for connecting said housings together, and a common instrumentality for actuating all of said diaphragms in unison.

16. In an instrument for reproducing sound, a plurality of sound sensitive devices, housings in which the sound sensitive devices are mounted and forming chambers on both sides of the diaphragms, one chamber of each diaphragm constituting the sound box, means for regulating the sizes of the sound boxes individually and independently, means for connecting the housin s together, and a common instrumentality or actuating all of said diaphragms in unison.

17. In an instrument for reproducing sound, a plurality of relatively independent diaphragm units including diaphragms and housings therefor and means for independently regulating the action of said dia phragms, means for directly actuating one of said diaphragms, and a common instrumentality connected with all of said diaphragms whereby all diaphragms are actuated from the directly actuated diaphragm.

18. In an instrument for reproducing sound, a plurality of relatively independent diaphragm units including diaphragms and housings therefor, means for independently regulating the size of the sound chamber of each diaphragm, means for independently` regulating the air pressure on each diaphragm, means connecting said diaphragml units together, means for directly actuatlng one of said diaphragms, and means connected with the directly actuated diaphragm and with the other diaphragms whereby all of said diaphragms are actuated in unison.

19. In an instrument for reproducing sound, a main casing having4 a partitioning member forming separate chambers, a' plurality of relatively independent diaphragm units, one carried in each chamber and each including a ldiaphragm and a frame therefor, a common instrumentality from which said diaphragms are actuated in unison, and means for independently regulating the`action of said diaphragm units.

20. In an instrument for reproducing sound, a main casing having a partitioning member forming separate chambers, a plurality of relatively independent diaphragm units, one carried -in each chamber and each including a diaphragm and a housing therefor enclosing the diaphragm, a common instrumentalityk from which .said diaphragms are actuated in-unison, and means for independently regulating the air pressure on said diaphragms, said means including a damper the housings.

structure regulating the admission of air to 21. An electromagnetic sound reproducer comprising in combination a main casing forming a chamber, a diaphragm closing one end of said chamber, an electromagnetic operating mechanism carried within said chamber and arranged to actuate said diaphragm,

a supplemental chamber supported from said main casing, a diaphragm carried within said supplemental chamber, and means whereby said electromagnetic operating mechanism operates each of said diaphragms for reproducing 'sound over a broad range of tone frequencies, said means being independent and peculiafto each diaphragm.

22. In a sound reproducer, a plurality of diaphragms, means for actuating said diahraOms in unison and means formin a free sound outlet passage at sides of said diaphragms which vibrate in phase with one another.

` 23. In a sound reproducer, a plurality of diaphragms, an electro-magnet having a balanced armature operatively connected to said diaphragms and means forming sound outlet passage at sides of said diaphragms which vibrate in phase with one another.

24:. In a sound reproducer, a plurality of diaphragms, means for actuating said diaphragms, means forming sound outlet passages at sides of said diaphragms which vibrate in phase with one another and means for controlling the sound from said passages.

25. In a sound reproducer, a plurality of diaphragms, means for actuating said diaphragms, means forming soundoutlet passages at sides of said diaphragms which vibrate in phase with one another and means forvcontrolling the sound from each passage.

26. In a device of the class described, two spaced diaphragms, actuating means for said diaphragms, comprising a long thin rod connected at its ends to said diaphragms and means forming sound outlet passages from sides of said diaphragms which vibrate in phase With one another.

27. In a' device of the class described; a frame, diaphragms mounted in said frames adjacent opposed ends of said frame, means for operatingL said diaphragms in unison and from the inner side of one diaphragm and from the outer side of the other diaphragm.

28. In a sound reproducer, a plurality of diaphragms, means for actuating said diaphragms in unison, means forming sound resonant chambers at opposite sides of each hereunto.

EARL H. FOLEY. 

